How can I add an array to a struct property in C?

Question

How can I add an array to a struct property in C? Here you have an example of what I want to accomplish:

#include <stdio.h>
#include <string.h>

typedef struct {
    char age;
    short number;
    int grades[10];
    char name[80];
    char address[120];
} Student;

Student s;

s.age = 23;
s.number = 10;
strcpy(s.name, "Jon");
strcpy(s.address, "Doe");

int oldGrades[10] = {1, 8, 2, 2, 4, 9, 9, 8, 4, 1};

s.grades = oldGrades; // Error: expression must be a modifiable lvalue

How can I add the array oldGrades to the property grades of my recently created object?

`s.grades = oldGrades;` --> `memcpy(s.grades, oldGrades, sizeof(oldGrades));` — David Ranieri, Nov 29 '18 at 19:07
If number is a phone number and not an id then it should be a string. — NathanOliver, Nov 29 '18 at 19:08
As an addendum to the other comments, you could also wrap the grades array in its own struct. You can copy the contents of a struct from one to another with assignment. Not suggesting it is good design practice, but just another technically correct way to achieve it. — Michael Petch, Nov 29 '18 at 19:37

kiran Biradar · Accepted Answer · 2018-11-29T19:19:14.963

1

You can manually copy the array contents using for loop.

for(int i =0;i<10;i++)
s.grades[i] = oldGrades[i];

Or you can use memcpy.

memcpy(s.grades, oldGrades, sizeof(oldGrades))

c doesn't provide facility s.grades = oldGrades to copy array by assignment.

edited Nov 29 '18 at 19:19

answered Nov 29 '18 at 19:17

kiran Biradar

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Introducing `memcpy()` way in this situation is a good solution but i think `for()`is better to a newbie. – EsmaeelE Nov 29 '18 at 19:46

How can I add an array to a struct property in C?

1 Answers1